James Collins' first league goal for the club sealed the three points, but Di Canio believes his board must invest in players if the club is to challenge for the title.
He said: "I'm happy because we got three points and that's the maximum you can get from a game. But I can't promise the fans now that we'll go up. It's very difficult.
"If we have one or two injuries that's ok, but if we have three or four that's different. It will be very tough to win the league.
"A team that really wants to go up needs to bring more players in. That is the message I send. I will commit 200% because I'm a loyal person, but in the next few weeks somebody needs to say whether they think this is enough.
"Obviously I think the manager can make a difference and I'm sure I can improve my players. But I'm not God. I am one of the best managers but I'm not God."